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Background and aims: Tillage system and crop rotation influences soil organic carbon (SOC) and total N (TN), but there remains considerable uncertainty in the response of C and N dynamics to fertilizer N inputs. A long-term (11-yr) experiment on a clay loam Orthic Humic Gleysol at Ridgetown, Ontario, Canada was used to evaluate the impact of fertilizer N applications (in-season zero N (−N) compared to (+N) 100 and 80 kg N ha yr. to corn ( Zea mays L.) and wheat ( Triticum aestivum L.), respectively) on soil attributes. Methods: The cropping systems consisted of continuous corn (CC), corn-soybean ( Glycine max L.) (C-S) and corn-soybean-wheat (C-S-W) rotations using conventional moldboard plough and no-till systems. Soil was collected from the 0-120 cm profile in 5, 10, and 20 cm increments and analyzed for SOC and TN. Results: The effect and interaction of N fertilization on soil attributes was highly dependent on crop rotation and tillage system. The gain in SOC and TN contents due to +N fertilizer was greatest (up to 31 and 57 % relative to the -N control, respectively) in the 0-20 cm depth with the C-S-W rotation, and lowest under CC, which showed no N fertilizer effect. However, differences in SOC and TN were not confined to the surface 20 cm, as N fertilizer treatments significantly influenced the contents at 20-60 and 60-120 cm in certain rotation and tillage systems; C-S-W was the most responsive to N fertilizer-induced SOC and TN gains. Conclusions: Using regression analysis, we found that higher SOC contents corresponded to lower variability in the 5-yr. mean corn yield, which suggests that the inclusion of winter wheat in a C-S rotation may have important implications for sustainable and resilient agroecosystems in humid, temperate climates. [ABSTRACT FROM AUTHOR]

Considers the factors that affect the concentrations of deoxynivalenol (DON) and fumonisin B1 (FB1) in grain harvested from corn fields across Ontario from 1993-2000. Ways by which seasons, weather and cultural practices affect the concentration of DON and FB1 in grains; Method by which corn growers can reduce DON and FB1 in harvested grain.

Determines the effect of previous and adjacent crop, tillage, field size and sampling direction on the number of viable airborne propagules of Gibberella zeae/Fusarium graminearum in southwestern Ontario. Fusarium head blight index; Percentage of seeds infected with Fusarium graminearum; Deoxynivalenol accumulation in seed of winter wheat from commercial fields; Spore trapping; Airborne inoculation.

Objective: To present a new approach in the evaluation and management of concussion from the athletic trainer's perspective.Background: The evaluation and management of concussion continues to be a controversial topic among sports medicine professionals. Inconsistent management, lack of objective data, and confusion concerning assessment techniques may lead to inappropriate decisions regarding when to return an athlete to competition after concussion. In this article, we provide recommendations and considerations for the certified athletic trainer in the management of concussion. We also present a quantifiable assessment technique that provides more information on which return-to-play decisions can be made; this technique can be used during the initial sideline examination as well as during subsequent follow-up examinations.Recommendations: Certified athletic trainers and team physicians should consistently use appropriate grading scales. Assessment of concussion should include a symptom checklist, the Balance Error Scoring System, and the Standardized Assessment of Concussion, and the results should be compared with the athlete's normal baseline scores. Follow-up neuropsychological and postural stability testing is recommended. Return-to-play decisions should be based on the grade of concussion, scores on objective tests, and presence of concussive symptoms during exertional activities. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) is a devastating disease of wheat because of direct detrimental effects on grain yield, quality, and marketability and production of mycotoxins (e.g. deoxynivalenol or DON). Conditions most favourable for the development of FHB are high humidity, frequent rainfall and relatively warm night temperatures at heading, especially in regions where host crop residues are present. These risk factors have resulted in a significant westward expansion of FHB in the Canadian prairies, while favouring continued development in Ontario, Quebec and the Maritimes. Since cultivar selection is a key integrated pest management (IPM) strategy, a systems approach that couples genetic resistance with management tactics is required. Thus, successful FHB mitigation is an ideal case study in Genotype (G) × Environment (E) × Management (M) interactions where more resistant cultivars (G) are grown in at-risk regions (E), and unique approaches to management (M) for sustainable wheat production are required. Since no cultivar is completely resistant to FHB, greater attention to management strategies is needed. The over-arching principle for FHB management is the manipulation of agronomic factors that facilitate completion of critical crop developmental phases, such as flowering, while doing so rapidly and uniformly, as a consequence of early sowing and increased seeding rates. These strategies and the adoption of practices involving proper fungicide selection, and optimal application timings and methods will lead to improved yield stability and quality in high-risk environments. This paper explores the potential synergies that exist for FHB mitigation when appropriate genetics are combined with an array of key agronomic strategies. [ABSTRACT FROM AUTHOR]